/*=========================================================================

  Program:   ORFEO Toolbox
  Language:  C++
  Date:      $Date$
  Version:   $Revision$


  Copyright (c) Centre National d'Etudes Spatiales. All rights reserved.
  See OTBCopyright.txt for details.

  Some parts of this code are derived from ITK. See ITKCopyright.txt
  for details.


     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/


// Software Guide : BeginLatex
//
// This example illustrates the use of the \code{SetPixel()} and
// \code{GetPixel()} methods.  These two methods provide direct access to the
// pixel data contained in the image. Note that these two methods are
// relatively slow and should not be used in situations where
// high-performance access is required. Image iterators are the appropriate
// mechanism to efficiently access image pixel data. %(See
// %Chapter~\ref{sec:ImageIteratorsChapter} on page
// %\pageref{sec:ImageIteratorsChapter} for information about image
// %iterators.)
//
// Software Guide : EndLatex

#include "otbImage.h"

int main(int, char *[])
{
  // First the image type should be declared
  typedef otb::Image<unsigned short, 2> ImageType;

  // Then the image object can be created
  ImageType::Pointer image = ImageType::New();

  // The image region should be initialized
  ImageType::IndexType start;
  ImageType::SizeType  size;

  size[0]  = 200;  // size along X
  size[1]  = 200;  // size along Y

  start[0] =   0;  // first index on X
  start[1] =   0;  // first index on Y

  ImageType::RegionType region;
  region.SetSize(size);
  region.SetIndex(start);

  // Pixel data is allocated
  image->SetRegions(region);
  image->Allocate();

  // The image buffer is initialized to a particular value
  ImageType::PixelType initialValue = 0;
  image->FillBuffer(initialValue);

  // Software Guide : BeginLatex
  //
  // The individual position of a pixel inside the image is identified by a
  // unique index. An index is an array of integers that defines the position
  // of the pixel along each coordinate dimension of the image. The IndexType
  // is automatically defined by the image and can be accessed using the
  // scope operator like \doxygen{itk}{Index}. The length of the array will match
  // the dimensions of the associated image.
  //
  // The following code illustrates the declaration of an index variable and
  // the assignment of values to each of its components.  Please note that
  // \code{Index} does not use SmartPointers to access it. This is because
  // \code{Index} is a light-weight object that is not intended to be shared
  // between objects. It is more efficient to produce multiple copies of
  // these small objects than to share them using the SmartPointer
  // mechanism.
  //
  // The following lines declare an instance of the index type and initialize
  // its content in order to associate it with a pixel position in the image.
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  ImageType::IndexType pixelIndex;

  pixelIndex[0] = 27;   // x position
  pixelIndex[1] = 29;   // y position
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // Having defined a pixel position with an index, it is then possible to
  // access the content of the pixel in the image.  The \code{GetPixel()}
  // method allows us to get the value of the pixels.
  //
  // \index{otb::Image!GetPixel()}
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  ImageType::PixelType pixelValue = image->GetPixel(pixelIndex);
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // The \code{SetPixel()} method allows us to set the value of the pixel.
  //
  // \index{otb::Image!SetPixel()}
  //
  // Software Guide : EndLatex

  // Software Guide : BeginCodeSnippet
  image->SetPixel(pixelIndex,   pixelValue + 1);
  // Software Guide : EndCodeSnippet

  // Software Guide : BeginLatex
  //
  // Please note that \code{GetPixel()} returns the pixel value using copy
  // and not reference semantics. Hence, the method cannot be used to
  // modify image data values.
  //
  // Remember that both \code{SetPixel()} and \code{GetPixel()} are inefficient
  // and should only be used for debugging or for supporting interactions like
  // querying pixel values by clicking with the mouse.
  //
  // Software Guide : EndLatex

  return EXIT_SUCCESS;

}
